Association of marital status with the incidence of suicide: A population-based Cohort Study in Japan (Miyagi cohort study)

Background: Marital status is one of the most frequently replicated predictors of suicide. The purpose of this study was to examine the effect of marital status on the risk of suicide by gender, using a large population-based cohort in Japan. Methods: The Miyagi cohort study was a population-based, prospective cohort study of Japanese adults aged between 40 and 64 years. Between June and August 1990, 47,604 participants residing in 14 municipalities of Miyagi Prefecture, Japan, completed a questionnaire on various health-related lifestyles, including marital status. During 18 years of follow-up, 146 of the participants committed suicide. We used the Cox proportional hazards regression model to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for suicide mortality according to marital status with adjustment for potential confounders. Results: A total of 106 and 40 deaths from suicide were recorded during 344,813 and 365,524 person-years of follow-up among 20,671 men and 21,076 women, respectively. We found that marital status was significantly associated with the risk of completing suicide only in men. Among men, after multivariate adjustment, HRs in reference to married were as follows: widowed or divorced, 2.84 (95% CI: 1.37-5.90); unmarried, 1.56 (95% CI: 0.67-3.64). A significantly increased risk of suicidal death was observed among widowed or divorced men, whereas no such trend was evident for women. Conclusions.: Our results suggest that men who are widowed or divorced, or unmarried, are at increased risk of suicide, whereas no such risk is evident for women. (C) 2013 Elsevier B.V. All rights reserved.